Old Ethanol Fuel – Add Fresh or Just Burn it?
08-01-2011, 07:32 PM
#41
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Location: sint maarten
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Well said, some times people have to blow stuff up before they learn. Well thats the way I learned about it in this case. Learn from my mistake, listen to what we are saying. I always go by the 1 month rule as Eddie spoke of. Don't just fill up your tank and top it off and keep it full all summer. Just pump the amount of fuel you will use in a couple of weeks. Don't let it get old.
08-01-2011, 07:32 PM
#42
Platinum Member
Platinum Member
Here is what is posted on a the Virgina Saltwater Website. Very interesting...
Ethanol Fuel
Boaters are now faced with a new problem - ethanol fuel. For years, gasoline contained MTBE, an additive which controls the fuel's octane properties. The additive is being phased out, and now much of the nation's fuel supply is a blend of 10% ethanol and 90% gasoline, commonly referred to as E-10 fuel.
Ethanol presents several problems to boaters. The immediate impact of the formulation is a loss of horsepower and fuel economy. Early indications show drops of 3-5 % in of both categories. The loss of range sounds small, but adds up on boats that are often already stretched to the limit in terms of fuel needs. Additionally, ethanol is a very effective solvent, and has a tendency to dissolve old coatings of varnish and dirt in existing fuel systems. This can lead to plugged fuel filters, and other mechanical problems.
The added amounts of particles associated with ethanol fuel may warrant upgrading filter systems. Many engineers are now recommending that boats using ethanol fuel need to use 10 micron filters. Pre-E-10 systems will likely be using 28 micron filters. Manufacturers such as Yamaha have been quick to respond to ethanol fuel use by introducing replacement 10 micron filters.
The corrosive nature of ethanol can affect fuel lines and other components, causing them to crack and fail. Many older boats will require replacement of all fuel hoses and possibly other system components. Especially affected are boats equipped with fiberglass tanks. Many older vessels must have the fiberglass tanks replaced prior to using E-10 fuels, or face certain engine failures.
Water in E-10 fuel is another problem that boaters must deal with. The introduction of water on E-10 fuel can be disasterous. E-10 can hold up to four teaspoons of water in suspension per gallon. Once this saturation point is exceeded, the solution separates and the gas floats on top while the ethanol and water mix on the bottom. This event is called "phase separation". Ethanol fuel can absorb enough water to reach it's phase separation point in just over 3 months at 70% humidity.
While the phase separation slurry in itself can cause problems by clogging fuel systems, the more immediate problem is that the remaining gasoline has now lost it's original octane value which can cause poor running and in some cases engine damage. When phase separation occurs, the fuel should be drained and replaced.
Fuel storage and winterization has to be handled differently when using E-10 fuels. Manufacturers are warning that fuels need to be stabilized if un-used for as little as 2 weeks. Not all stabilizers are known to be E-10 compatible. Non-alcohol based fuel stabilizer additives are a must for ethanol fuel.
Ethanol Fuel
Boaters are now faced with a new problem - ethanol fuel. For years, gasoline contained MTBE, an additive which controls the fuel's octane properties. The additive is being phased out, and now much of the nation's fuel supply is a blend of 10% ethanol and 90% gasoline, commonly referred to as E-10 fuel.
Ethanol presents several problems to boaters. The immediate impact of the formulation is a loss of horsepower and fuel economy. Early indications show drops of 3-5 % in of both categories. The loss of range sounds small, but adds up on boats that are often already stretched to the limit in terms of fuel needs. Additionally, ethanol is a very effective solvent, and has a tendency to dissolve old coatings of varnish and dirt in existing fuel systems. This can lead to plugged fuel filters, and other mechanical problems.
The added amounts of particles associated with ethanol fuel may warrant upgrading filter systems. Many engineers are now recommending that boats using ethanol fuel need to use 10 micron filters. Pre-E-10 systems will likely be using 28 micron filters. Manufacturers such as Yamaha have been quick to respond to ethanol fuel use by introducing replacement 10 micron filters.
The corrosive nature of ethanol can affect fuel lines and other components, causing them to crack and fail. Many older boats will require replacement of all fuel hoses and possibly other system components. Especially affected are boats equipped with fiberglass tanks. Many older vessels must have the fiberglass tanks replaced prior to using E-10 fuels, or face certain engine failures.
Water in E-10 fuel is another problem that boaters must deal with. The introduction of water on E-10 fuel can be disasterous. E-10 can hold up to four teaspoons of water in suspension per gallon. Once this saturation point is exceeded, the solution separates and the gas floats on top while the ethanol and water mix on the bottom. This event is called "phase separation". Ethanol fuel can absorb enough water to reach it's phase separation point in just over 3 months at 70% humidity.
While the phase separation slurry in itself can cause problems by clogging fuel systems, the more immediate problem is that the remaining gasoline has now lost it's original octane value which can cause poor running and in some cases engine damage. When phase separation occurs, the fuel should be drained and replaced.
Fuel storage and winterization has to be handled differently when using E-10 fuels. Manufacturers are warning that fuels need to be stabilized if un-used for as little as 2 weeks. Not all stabilizers are known to be E-10 compatible. Non-alcohol based fuel stabilizer additives are a must for ethanol fuel.
08-01-2011, 07:55 PM
#43
Platinum Member
Platinum Member
Here are some exserts from Mercury Marines position on using E-10 fuel in their products. I am going to start doing some things differently this winter.
What is phase separation, and how do I deal with it?
If significant amounts of water are present in a fuel tank with gasoline that contains ethanol, the water will be
drawn into the fuel until the saturation point is reached for the three-component mixture of water + gasoline +
ethanol. Beyond this level of water, phase separation could cause most of the ethanol and water to separate
from the bulk fuel and drop to the bottom of the tank, leaving gasoline with a significantly reduced level of
ethanol in the upper phase (see Figure 1 below). If the lower phase of water and ethanol is large enough to
reach the fuel inlet, it could be pumped directly to the engine and cause significant problems. Even if the ethanol
water phase at the bottom of the tank is not drawn into the fuel inlet, the reduced ethanol level of the fuel
reduces the octane rating by as much as 3 octane numbers, which could result in engine problems. The level at
which phase separation can occur is determined by a number of variables, including the amount of ethanol, the
composition of the fuel, the temperature of the environment and the presence of contaminants. It is very
important (A) that the system is inspected for significant quantities of water in the tank before using gasoline
with ethanol and (B) to limit exposure of the fuel tank to excess water. If phase separation has occurred, it is
necessary to completely remove all free water from the system and replace the fuel before continuing operation.
Otherwise, engine problems could occur.
Figure 1: Sample of fuel from fuel tank in which phase separation has occurred. The upper phase is gasoline
with a reduced level of ethanol. The lower level is a mixture of ethanol and water.
Is an additive available that can prevent phase separation?
There is no practical additive that can prevent phase separation from occurring. The only practical solution is to
keep water from accumulating in the tank in the first place.
Are there any additives that can allow the phase-separated mixture to remix when added to the fuel tank?
No, the only way to avoid further problems is to remove the water, dispose of the depleted fuel, clean the tank
and start with a fresh, dry load of fuel.
Is there a simple solution to water condensation in the tank as a result of ethanol?
It is best to maintain a full tank of fuel when the engine is not in use. This will reduce the void space above the
fuel and will reduce the flow of air in and out of the tank with changes in temperature. This will reduce
condensation on the internal walls of the tank and will limit exposure of the ethanol in the fuel to humidity and
condensation.
What should be done when storing boats with ethanol-blended fuels for extended periods?
When preparing to store a boat for extended periods of two months or more, it is best to completely remove all
fuel from the tank. If it is difficult or not possible to remove the fuel, maintaining a full tank of fuel with a fuel
stabilizer added to provide fuel stability and corrosion protection is recommended. A partially full tank is not
recommended because the void space above the fuel allows air movement that can bring in water through
condensation as the temperature cycles up and down. This condensation potentially becomes a problem.
Mercury Marine Fuel System Treatment & Stabilizer can help maintain fuel systems in storage. It contains
oxidation inhibitors to reduce oxidation and gum formation, metal chelating agents to protect metal components
from corrosion, water absorbing agents to reduce the presence of free water, and dispersants to help suspend
and disperse debris. It is best used by adding to the tank at the recommended dosage, running the engine for
10 minutes to allow the system to be cleaned, shutting off the fuel valve to interrupt the fuel supply and allow the
engine to run until it stops, topping off the tank until it's full, and capping any openings to reduce the amount of
exchange with the air that might bring in condensation.
What is phase separation, and how do I deal with it?
If significant amounts of water are present in a fuel tank with gasoline that contains ethanol, the water will be
drawn into the fuel until the saturation point is reached for the three-component mixture of water + gasoline +
ethanol. Beyond this level of water, phase separation could cause most of the ethanol and water to separate
from the bulk fuel and drop to the bottom of the tank, leaving gasoline with a significantly reduced level of
ethanol in the upper phase (see Figure 1 below). If the lower phase of water and ethanol is large enough to
reach the fuel inlet, it could be pumped directly to the engine and cause significant problems. Even if the ethanol
water phase at the bottom of the tank is not drawn into the fuel inlet, the reduced ethanol level of the fuel
reduces the octane rating by as much as 3 octane numbers, which could result in engine problems. The level at
which phase separation can occur is determined by a number of variables, including the amount of ethanol, the
composition of the fuel, the temperature of the environment and the presence of contaminants. It is very
important (A) that the system is inspected for significant quantities of water in the tank before using gasoline
with ethanol and (B) to limit exposure of the fuel tank to excess water. If phase separation has occurred, it is
necessary to completely remove all free water from the system and replace the fuel before continuing operation.
Otherwise, engine problems could occur.
Figure 1: Sample of fuel from fuel tank in which phase separation has occurred. The upper phase is gasoline
with a reduced level of ethanol. The lower level is a mixture of ethanol and water.
Is an additive available that can prevent phase separation?
There is no practical additive that can prevent phase separation from occurring. The only practical solution is to
keep water from accumulating in the tank in the first place.
Are there any additives that can allow the phase-separated mixture to remix when added to the fuel tank?
No, the only way to avoid further problems is to remove the water, dispose of the depleted fuel, clean the tank
and start with a fresh, dry load of fuel.
Is there a simple solution to water condensation in the tank as a result of ethanol?
It is best to maintain a full tank of fuel when the engine is not in use. This will reduce the void space above the
fuel and will reduce the flow of air in and out of the tank with changes in temperature. This will reduce
condensation on the internal walls of the tank and will limit exposure of the ethanol in the fuel to humidity and
condensation.
What should be done when storing boats with ethanol-blended fuels for extended periods?
When preparing to store a boat for extended periods of two months or more, it is best to completely remove all
fuel from the tank. If it is difficult or not possible to remove the fuel, maintaining a full tank of fuel with a fuel
stabilizer added to provide fuel stability and corrosion protection is recommended. A partially full tank is not
recommended because the void space above the fuel allows air movement that can bring in water through
condensation as the temperature cycles up and down. This condensation potentially becomes a problem.
Mercury Marine Fuel System Treatment & Stabilizer can help maintain fuel systems in storage. It contains
oxidation inhibitors to reduce oxidation and gum formation, metal chelating agents to protect metal components
from corrosion, water absorbing agents to reduce the presence of free water, and dispersants to help suspend
and disperse debris. It is best used by adding to the tank at the recommended dosage, running the engine for
10 minutes to allow the system to be cleaned, shutting off the fuel valve to interrupt the fuel supply and allow the
engine to run until it stops, topping off the tank until it's full, and capping any openings to reduce the amount of
exchange with the air that might bring in condensation.
